Issue with Bosch Platinums and Coil pack ignitions

[DavidA]

I came across this by chance, very interesting:

http://au.geocities.com/ozbrick850/engine-sparkboschplat.html

Bosch acknowledges a problem with using their Bosch Platinum spark plugs in engines with ignition systems that employ 1 coil for each pair of spark plugs (also known as a "waste spark ignition system").


The problem that Bosch has acknowledged when using their Platinum plugs in engines with waste spark ignition systems stems from the tendency of electrode metal to get transferred depending upon the polarity (direction of current flow) of the spark. In waste spark ignition systems, 1/2 of the plugs always see reverse polarity sparks. Given the very narrow platinum
center electrode of the Bosch Platinums, performance will be degraded more significantly when reverse polarity sparks will cause material to be transferred from the large ground/outer electrode onto the narrow platinum center electrode's exposed end surface.

In cars with conventional (1 coil) ignition systems, every spark is of the same polarity, for which the Bosch Platinums are optimized, leaving them to deliver their designed-in advantages, which include:

o reaching self-cleaning temperature faster ("than any other plug")

o maintaining the spark gap and low firing voltage requirement throughout their service life. (even in my high-stress turbocharged application

 

[Koz]

NGKs are the best plugs made. I say this from 30 years of experience with high performance motorcycle engines and many years with foreign cars.

Koz

 

[Iowa4Runner]

:iagree:

Luckily Toyota gave us a coil for each cylinder so we don't have to worry about reverse spark polarity...

 

[JungleJim]

NGKs are the best plugs made.Koz

That is up for opinion, but the best plug depends on the application.

 

[Koz]

That is up for opinion, but the best plug depends on the application.

Absolutely!

Koz